Thorium – a good idea? WISE, Jan 15 (translation by Noel Wauchope) “………….Now with the fear of further nuclear weapons proliferation increasing, the nuclear industry looks to another cycle, based on thorium instead of uranium. But with a thorium reactor one can also make nuclear weapons material. The Thorium reactor is not quite there yet. The technique is not yet out-developed, let alone tried. All serious scientists think it will still take several decades before there reactors are available for commercial use.
And so does the whole “climate” argument; if you want to do something about climate change (replace coal plants Thorium power plants) it will have to be done very quickly, not over 20 years. Moreover the many tens of billions of dollars to build a thorium cycle and infrastructure could be better spent on truly clean and endless sources. Moreover, the thorium cycle has serious drawbacks……..
Because plutonium is a chemically very different ftrom uranium, it is quite easy to identify from spent fuel rods. Uranium-235 or other isotopes * (U-232 and U-233)are much more difficult, because they are chemically indistinguishable from the rest of the uranium………
Thorium is often mentioned. It is an ore which can be recovered like uranium in large mines. Although thorium itself is not very radioactive, many decay products of thorium are. It expires in stages to include the noble gas 220Rn presenting the risk of contamination. The biggest health threat of thorium is if ingested or inhaled. The alpha radiation can not penetrate the skin, but if ingested accumulates in the liver, spleen, lymph nodes and bones. The “biological half-life ‘of thorium is about 22 years, which in practice means that the alpha radiation damages during the rest of life, and thereby increases the risk of liver cancer and leukemia. This makes mining of thorium a tricky business.
It is not self-fissile but neutron radiation in a nuclear reactor converts it to it fissionable U-233 and U-232 waste product. This is material that can be used for the production of nuclear weapons. So there is indeed in a thorium reactor, not plutonium, but other proliferation-sensitive material.
Thorium reactors are – according to the proponents of this technique – so also much safer than current reactors. For example, in a liquid fluoride thorium reactor (LFTR) the fuel is not processed as a solid but is dissolved in a molten fluoride salt. This molten salt is also used as a refrigerant and as fuel. It remains stable at high temperatures and controllable. The advocates claim that ‘the runaway of the reactor in a thorium-central’ is impossible. The neutrons released during the reactions can be immediately absorbed by the thorium atoms in the mixture, causing the atoms to be in turn suitable for fission. It is also possible to use materials other than thorium, plutonium, for example, to add to the mixture. Advocates say so; it is a way to get rid of our plutonium; we use it just as a fuel in the thorium plant.
But it is questionable whether the thorium cycle is really a better guarantee against the danger of proliferation. Although no plutonium is produced there is a method to extract the nuclear material U-233 quite easily and efficiently from irradiated thorium reactor rods. Thorium ie first becomes protactinium (PA-233), which decays with a half-life of 27 days to U-233. To select from the reactor fuel rods after about a month to, it is possible to separate the PA-233 from the thorium. This can also be in a small lab, there is no need for large or complex factory. Then you just have to wait a few months until all the protactinium is spontaneously transformed into highly pure uranium-233. Eight pounds of this material is already enough to make an atomic bomb.
Hence the thorium cycle can be diverted to the production of atomic bombs. This removes a major advantage claimed. Proponents say of thorium; “There are easier ways to get nuclear material, so terrorists or countries that seek nuclear weapons do not really want to use thorium reactors.” But that’s a rather strange reasoning; it is also easier to commit a murder with a gun than with a knife. Why do not you go do not advocate the possession of a knife?
A thorium plant, compared to uranium plants, produces little long-lived radioactive waste. But not even this type of plant is still producing waste that remains dangerous for 240,000 years and people and the environment must be stored and fully protected. The problem of high-level nuclear waste is not so much the volume (quantity) but the toxicity and radiation intensity. Whether you need to find a solution for 100 or 500 pounds is not as relevant, the point is that there is still no definitive accepted method existing to store this hazardous waste safely for thousands of years.
The nuclear industry has a problem; it now fully recognizes that the problems with the current (Uranium) cycle are too large. So it now looks to a whole new cycle based on thorium The owners of the now hundreds of operating nuclear power plants, the builders of the uranium-based power plants, the thousands of people who earn their living from extracting uranium will not go welcome the call for a Thorium industry. This has resulted in the odd dichotomy between the people who believe in the Thorium Cycle and the people who believe in the Uranium Cycle. Meanwhile there are the scientists who want to explore new fields of research especially those who advocate Thorium power plants; they want to be assured that they can can certainly do some decades (fundamental) research.
Too late, too expensive
Do not forget; the thorium reactor is not quite there yet, all serious scientists think it will still take several decades before there reactors are available for commercial use. And so does the whole “climate” argument; if you want to do something about climate change (replace coal plants Thorium power plants) that will have to be done very quickly, not waiting over 20 years to begin. Moreover, it will cost many tens of billions of dollars to build a thorium cycle and infrastructure. That money can be spent better ongenuinely clean and endless sources.http://www.wisenederland.nl/kernenergie/thorium-een-goed-idee-0